Typical sand spreading vehicles have a box mounted over the rear portion of the vehicle for containing sand. Centrally located in the bottom of the box is a conveyor for withdrawing sand in controlled portions for distribution on a road surface. This conveyor typically runs the length of the bin from its rear to its front end centrally located and may consist of a chain "ladder" that circulates in a closed loop, dragging sand with the sliding "rungs" forwardly for delivery to an opening for deposit on the roadway.
A further feature of such vehicles is that the sand containing bin may be tipped, in certain configurations, in two directions. The bin may be tipped upwardly at its forward end to dump sand `en mass` out a rearward, hinged, end panel when excess sand has been loaded and it is desired to empty the vehicle. On occasion such bins may also be tipped sideways about a longitudinal axis aligned with the vehicle's direction of travel. This sideways tipping does not occur to an extensive degree and is not intended for emptying the bin. Rather it is directed to passing sand from the outside bottom corners of the bin to the central conveyor. This tipping action is needed when the bin has a small amount of sand remaining on its bottom, and the sand is no longer sliding spontaneously towards the central conveyor.
To avoid the cost of this sideways tipping mechanism, some spreader vehicles are built with bins having flat, inwardly tapering, "V"-shaped bottom surfaces. In such cases, the sand slides spontaneously to the central conveyor because of the downward slope of the two bottom panels on either side of the conveyor.
A disadvantage of the tapered-bottom bin design is that for a given load of sand, the center of gravity of the loaded vehicle is higher off of the ground than for a flat-bottomed bin. The higher the center of gravity of a vehicle, the greater is the risk that it may tip sideways on uneven terrain. Allowing that such vehicles are built to standards of stability, typically government-enforced, the presence of a tapered bottom reduces the load capacity of such a vehicle.
This invention addresses the objective of maximizing the load capacity of a spreader vehicle without incurring the complications and expense of a side-tipping mechanism.
The invention in its general form will first be described, and then its implementation in terms of specific embodiments will be detailed with reference to the drawings following hereafter. These embodiments are intended to demonstrate the principle of the invention, and the manner of its implementation. The invention in its broadest and more specific forms will then be further described, and defined, in each of the individual claims which conclude this Specification.